Diamond-like carbon (DLC) coatings are used in many different fields. These coatings may be applied to many different substrates and may provide desired mechanical, electrical, optical, magnetic, chemical, biologic, and/or aesthetic properties. For example, the durability and performance of many machine parts can be enhanced by DLC thin film coatings by providing desired mechanical properties including, for example, wear resistance, controlled friction coefficients, strength, and/or fracture toughness.
Metal-containing amorphous carbon (Me-aC) and metal-containing amorphous hydrocarbon (Me-aC:H) coatings are two similar DLC coatings. These coatings are characterized by nanocrystalline metal-carbide clusters embedded in an amorphous carbon (aC) or an amorphous hydrocarbon (aC:H) matrix. Because these coatings may provide desirable tribologic properties and may have good adhesion properties when applied to many substrates, they are often used to protect machine parts.
Me-aC and Me-aC:H coatings may be produced using a number of commercially available processes, including a number of different vapor deposition processes. The processes used to produce these coatings may be controlled by computerized recipe managers, which may adjust deposition system variables to attain a certain level of coating reproducibility. However, for some applications, improved control of coating production to attain even better reproducibility may be needed. Particularly, for some applications it may be desirable to closely control deposition conditions to provide a desired coating composition and structure.
One method for producing a thin film coating is described in U.S. Pat. No. 5,405,645, issued to Sevillano on Apr. 11, 1995 (hereinafter “the '645 patent”). The method of the '645 patent includes adjusting gas flow rates within a microwave plasma generator to maintain a ratio of Carbon-2 (C2) and hydrogen-alpha (Hα) emission intensities within a certain range. Control of the ratio of C2 to Hα emission, according to the method of the '645 patent, may increase the rate of film deposition.
Although the method of the '645 patent may produce a suitable thin film coating, the method has several drawbacks. The method of the '645 patent is intended for high-quality diamond film production, which may not be desirable for some applications. Further, production of high-quality diamond films may require processing conditions which may alter or damage some substrate materials. In addition, the method of the '645 patent does not provide a method for producing Me-aC or Me-aC:H coatings with reproducible microstructural and physical properties.
The present disclosure is directed to overcoming one or more of the problems or disadvantages in the prior art thin film coating production systems.